Armadillos and Their Role in Treating Leprosy (11/2/2006) If it weren’t for an unusual mammal, the nine-banded armadillo (Dasypus novemcinctus), very little progress would have been made in collecting scientific data on leprosy, or Hansen’s disease. The cause of the disease is a bacterium, Mycobacterium leprae (M. leprae), which multiplies very slowly—about once every two weeks--and has never been grown in any acceptable bacteriological medium or in cell culture. Many different animal species were tested to find a suitable model for leprosy research, and armadillos were one of the few that could be infected with M. leprae. Breast Cancer: What We Learned from Mice (11/9/2006) Research focusing on the causes of cancer had its origin in studies of chickens and mice, not humans. Experimental cancer research first became possible when investigators succeeded in transplanting tumors from one animal to another of the same species. In 1911, Peyton Rous prepared an extract from a sarcoma of a Plymouth Rock hen that had a large tumor growing on its breast. He inoculated small pieces of the tumor into healthy chickens of the same species. The chickens developed tumors of the same type as the original chicken. Later, he found that the tumors could be transferred without the use of intact cells, but rather with a cell-free filtrate that eliminated any bacteria. Rous proposed that the tumors were caused by a “filterable agent,” the term used at that time to describe viruses (1, 2). Scientific dogma held that cancer was not caused by an infectious agent, and scientists considered the “bird tumors” an exception that occurred only in chickens. Can Zebra Finches Tell Us How We Learn to Talk - and Walk (9/8/2008) The next time someone calls you a birdbrain, say “Thanks! That’s how I was able to learn to talk, walk, and do so many amazingly complex sequential movements.” Designer Mice Aim Gene Targeting at Mysterious Childhood Cancer (2/13/2009) A new designer mouse model reveals the mysterious origin of a cancer, synovial sarcoma, which strikes mainly teens and young adults. It turns out that this very poorly understood cancer starts in the very well understood skeletal muscles. Dogs That Lay Down on the Job Help Researchers (12/16/2008) Studies of narcoleptic dogs revealed that the disorder was caused by only one gene. This triggered a major gene hunt, which was spearheaded by Dr. Emmanuel Migot shortly after he arrived at Standford from Paris in the late 1980's. Fruitful Endeavor: Tiny Fruit Flies Test Drugs to Correct Fragile X Gene Damage (2/13/2009) The discovery of the gene responsible for fragile X syndrome, the most frequently inherited form of mental retardation in humans, was the “first major human triumph of the Human Genome Project,” but almost all the discoveries in fragile X since then have been made in studies of fruit flies and mice. What’s been lacking is a medical treatment. Now those fruit flies are pointing scientists in a direction these researchers hope will be – well -- fruitful! In 2008, the NIH-funded geneticist who discovered the fragile X gene reports that his team has identified drugs—already being used by humans for other conditions—that alter fragile X-related behaviors and abnormalities in the biochemistry and brain wiring of affected flies. The research team expects clinical trials to begin in humans within two years. How Mice Helped Combat Childhood Leukemia (11/9/2006) Acute lymphocytic leukemia (ALL), the most common form of childhood cancer, occurs when white blood cells produced in the bone marrow begin to reproduce uncontrollably. The huge numbers of immature white blood cells interfere with the development and functioning of oxygen-carrying red blood cells and clot-forming platelets. In the 1930s, the incidence of ALL began to rise almost exclusively in children. Without treatment, children seldom survived beyond three months after diagnosis. Up to the close of World War II, the only available treatments for cancer were surgery and irradiation. These standard treatments were of little value for this type of cancer because there were no discrete tumors to eliminate. In leukemia, cancer cells are dispersed in organs and blood throughout the body. Treatment with drugs and chemical compounds that were effective against other diseases had not yet been shown to be helpful in cancer. Making Medicines from Poisonous Snakes (12/18/2008) Poisonous snakes may some day save your life now that medical researchers are harnessing the healing potential of their venom. The Hormonal Cycle of Female Rats Provides Clues to a New Treatment for Brain Injury (8/25/2008) For more than 30 years, there has been no new effective treatment for the hundreds of thousands of people who suffer traumatic brain injury (sudden physical damage to the brain) every year. A few doctors believed women often – not always – appeared to recover better than men with similar injuries. Not everybody believed them, but what if they were they right? And if so, why? Neuroscientist Don Stein set out to discover if there was something about being female that might protect the injured brain. He could never have found the surprising answer he did without the help of rats. When he used that answer to improve recovery after head injury in both female and male rats, the next question was whether the new treatment would work in humans. Zebrafish: Helping Scientists Understand Human Genetic Diseases (11/9/2006) The zebrafish Danio rerio (ZF) has proven to be an excellent research model for determining the functions of genes in vertebrates. Using the powerful tools of modern molecular biology, researchers have the unique opportunity to study zebrafish DNA fragments that act during embryonic development. Scientists recognize that they can learn a lot about the functions of human genes by examining the genes of simpler organisms such as fruit flies, worms, yeasts, and mice because many of the genes in these species have been conserved throughout evolution. The ZF, a one- to two-inch long aquarium fish found in the rivers of India and available in pet stores, may be added to the list of important animal models for identifying the functions of genes for a broad range of developmental disorders and diseases. An atlas of the ZF embryo at various stages of development is in preparation .